Short leg walkers are generally formed with a rigid, rocker sole designed to allow the patient or user to roll through a gait cycle while immobilizing the ankle and the foot and without bending of the foot at the metatarso-phalangeal joint. Typically, two stabilizer bars are attached to the sole on respective sides of the ankle and extend up the sides of a leg approximately three quarters of the way up the calf. The lower leg and foot are wrapped in a foam liner which closes along the front of the shin and top of the foot and which fits in between the two stabilizer bars. Typically, three VELCRO.RTM. type hook and loop form fastener straps are wrapped around the lower leg enclosed in the foam liner and around the stabilizer bars to prevent the leg from bending at the ankle. Such hook and loop type fastener straps are also used to provide compression to the lower leg. One or two additional hook and loop type fastener straps are generally employed across the dorsum of the foot to hold the foot firmly against the inner sole of the walker. Such short leg walkers are most often used in lieu of a cast when there has been severe trauma or surgery to the ankle or foot, with the immobilization and compression of the lower leg, foot and ankle enhancing the healing process.
In such prior art short leg walkers, the stabilizer bars or stirrups are rigid, flat rods connected at their lower ends to the sole of the walker and extend to opposite sides of the leg. Such stirrups are generally of two different heights, a taller style that extends to just below the fibular neck, and a shorter style that extends approximately 4 to 6 inches above the ankle. There is usually a space between the stirrups and the medial and lateral malleolus to prevent friction. This space prevents the necessary compression of the short leg walker around the ankles, and more particularly in the Achilles triangle and distal to the malleoli. Since injuries, surgeries, etc. involving the ankle produce edema in the area, it is vital to have focal compression in the area to minimize edema.
In the past, plaster or fiberglass casts have been recognized as the ideal structure in initially dealing with these injuries. However, after the first few days, the edema subsides and the cast becomes loose on the leg, ankle and foot, no longer providing the necessary compression and rendering the cast uncomfortable while lacking the immobilization necessary for proper healing of the involved tissue.
In the prior short leg walkers, the rocker sole design used in most such walkers poses several problems for the wearer. A true rocker sole must be of sufficient thickness (height) so that an uninterrupted roll is possible through the complete gait cycle. This extra height produces a leg length discrepancy with the unaffected limb that places undue pressure on the knee, hip and lower back of the user. In those cases where arthritic charges are present, the discomfort is even more pronounced.
A second problem with the rocker sole design short leg walker is that the rocker sole is unstable when the wearer is in a stationary or standing position and movement is unnecessary and uncomfortable. Because there are no flat portions on a rocker sole, there are no natural resting points for the leg, ankle and foot encased in the short length leg walker. When the wearer is standing in a rocker sole, the wearer most often rolls back on the heel, creating pressure on the knee and hip and slight hyperextension of the knee. Where the shoe portion of the brace has no heel counter, additional instability at the sub-talar and mid-tarsal areas of the foot is created.
In such prior art short length leg walkers, the double post design utilizing the multiple VELCRO.RTM. opposite type hook and loop fastener straps is intended to provide stabilization of the ankle and also provide compression to help reduce the edema associated with foot and ankle trauma. The area where compression is most needed lies in the Achilles triangle located behind the malleoli (ankle bone) as well as underneath and in front of the malleoli. The hook and loop type fastener straps do provide some compression, but instead of acceptable general compression, the compression more often takes the form of bands of localized pressure directly underneath the strap or straps themselves. Further, the two posts that aid in stabilization of the leg and ankle exacerbate this problem because they are designed to be the thickest over the ankle and for that reason do not conform at all to the lower leg and ankle where compression is most needed.
It is therefore a primary object of the present invention to eliminate the problems above commonly associated with known short leg walkers and to provide a more viable option to casting the lower leg when subject to surgery and trauma.
It is also a principal object of this invention to provide a lower leg, ankle and foot brace constituting an improved short leg walker which provides immobilization characterized by uniform, adjustable compression, which prevents torsion of the leg, ankle and foot as well as dorsiflexion and plantar flexion at the ankle joint, to further restrict motion at the metatarso-phalangeal joint, thereby immobilizing the ankle and foot joints and at the same time providing a shoe or boot type enclosure for greater wearer comfort and stability.
Other advantages of the present invention will become apparent from the description of the preferred embodiments and from the accompanying drawings.